libext2fs: add new hooks to support large allocations

Add a new get_alloc_blocks hook and a block_alloc_stats_range hook so
that e2fsck can capture allocation requests spanning more than a
block to its block_found_map.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index e87643a..3777e42 100644 (file)
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -3934,6 +3934,26 @@ static errcode_t e2fsck_get_alloc_block(ext2_filsys fs, blk64_t goal,
        return (0);
 }
 
+static errcode_t e2fsck_new_range(ext2_filsys fs, int flags, blk64_t goal,
+                                 blk64_t len, blk64_t *pblk, blk64_t *plen)
+{
+       e2fsck_t ctx = (e2fsck_t) fs->priv_data;
+       errcode_t       retval;
+
+       if (ctx->block_found_map)
+               return ext2fs_new_range(fs, flags, goal, len,
+                                       ctx->block_found_map, pblk, plen);
+
+       if (!fs->block_map) {
+               retval = ext2fs_read_block_bitmap(fs);
+               if (retval)
+                       return retval;
+       }
+
+       return ext2fs_new_range(fs, flags, goal, len, fs->block_map,
+                               pblk, plen);
+}
+
 static void e2fsck_block_alloc_stats(ext2_filsys fs, blk64_t blk, int inuse)
 {
        e2fsck_t ctx = (e2fsck_t) fs->priv_data;
@@ -3953,6 +3973,28 @@ static void e2fsck_block_alloc_stats(ext2_filsys fs, blk64_t blk, int inuse)
        }
 }
 
+static void e2fsck_block_alloc_stats_range(ext2_filsys fs, blk64_t blk,
+                                          blk_t num, int inuse)
+{
+       e2fsck_t ctx = (e2fsck_t) fs->priv_data;
+
+       /* Never free a critical metadata block */
+       if (ctx->block_found_map &&
+           ctx->block_metadata_map &&
+           inuse < 0 &&
+           ext2fs_test_block_bitmap_range2(ctx->block_metadata_map, blk, num))
+               return;
+
+       if (ctx->block_found_map) {
+               if (inuse > 0)
+                       ext2fs_mark_block_bitmap_range2(ctx->block_found_map,
+                                                       blk, num);
+               else
+                       ext2fs_unmark_block_bitmap_range2(ctx->block_found_map,
+                                                       blk, num);
+       }
+}
+
 void e2fsck_use_inode_shortcuts(e2fsck_t ctx, int use_shortcuts)
 {
        ext2_filsys fs = ctx->fs;
@@ -3976,4 +4018,7 @@ void e2fsck_intercept_block_allocations(e2fsck_t ctx)
        ext2fs_set_alloc_block_callback(ctx->fs, e2fsck_get_alloc_block, 0);
        ext2fs_set_block_alloc_stats_callback(ctx->fs,
                                                e2fsck_block_alloc_stats, 0);
+       ext2fs_set_new_range_callback(ctx->fs, e2fsck_new_range, NULL);
+       ext2fs_set_block_alloc_stats_range_callback(ctx->fs,
+                                       e2fsck_block_alloc_stats_range, NULL);
 }

diff --git a/lib/ext2fs/alloc.c b/lib/ext2fs/alloc.c
index 4c3b620..86e7f99 100644 (file)
--- a/lib/ext2fs/alloc.c
+++ b/lib/ext2fs/alloc.c
@@ -379,12 +379,32 @@ errcode_t ext2fs_new_range(ext2_filsys fs, int flags, blk64_t goal,
        blk64_t start, end, b;
        int looped = 0;
        blk64_t max_blocks = ext2fs_blocks_count(fs->super);
+       errcode_t (*nrf)(ext2_filsys fs, int flags, blk64_t goal,
+                        blk64_t len, blk64_t *pblk, blk64_t *plen);
 
        dbg_printf("%s: flags=0x%x goal=%llu len=%llu\n", __func__, flags,
                   goal, len);
        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
        if (len == 0 || (flags & ~EXT2_NEWRANGE_ALL_FLAGS))
                return EXT2_ET_INVALID_ARGUMENT;
+
+       if (!map && fs->new_range) {
+               /*
+                * In case there are clients out there whose new_range
+                * handlers call ext2fs_new_range with a NULL block map,
+                * temporarily swap out the function pointer so that we don't
+                * end up in an infinite loop.
+                */
+               nrf = fs->new_range;
+               fs->new_range = NULL;
+               retval = nrf(fs, flags, goal, len, pblk, plen);
+               fs->new_range = nrf;
+               if (retval)
+                       return retval;
+               start = *pblk;
+               end = *pblk + *plen;
+               goto allocated;
+       }
        if (!map)
                map = fs->block_map;
        if (!map)
@@ -432,7 +452,7 @@ errcode_t ext2fs_new_range(ext2_filsys fs, int flags, blk64_t goal,
                                   "blk=%llu--%llu %llu\n",
                                   __func__, goal, goal + len - 1,
                                   *pblk, *pblk + *plen - 1, *plen);
-
+allocated:
                        for (b = start; b < end;
                             b += fs->super->s_blocks_per_group)
                                clear_block_uninit(fs,
@@ -457,6 +477,21 @@ errout:
        return retval;
 }
 
+void ext2fs_set_new_range_callback(ext2_filsys fs,
+       errcode_t (*func)(ext2_filsys fs, int flags, blk64_t goal,
+                              blk64_t len, blk64_t *pblk, blk64_t *plen),
+       errcode_t (**old)(ext2_filsys fs, int flags, blk64_t goal,
+                              blk64_t len, blk64_t *pblk, blk64_t *plen))
+{
+       if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
+               return;
+
+       if (old)
+               *old = fs->new_range;
+
+       fs->new_range = func;
+}
+
 errcode_t ext2fs_alloc_range(ext2_filsys fs, int flags, blk64_t goal,
                             blk_t len, blk64_t *ret)
 {

diff --git a/lib/ext2fs/alloc_stats.c b/lib/ext2fs/alloc_stats.c
index aca5004..3949f61 100644 (file)
--- a/lib/ext2fs/alloc_stats.c
+++ b/lib/ext2fs/alloc_stats.c
@@ -145,4 +145,20 @@ void ext2fs_block_alloc_stats_range(ext2_filsys fs, blk64_t blk,
        }
        ext2fs_mark_super_dirty(fs);
        ext2fs_mark_bb_dirty(fs);
+       if (fs->block_alloc_stats_range)
+               (fs->block_alloc_stats_range)(fs, blk, num, inuse);
+}
+
+void ext2fs_set_block_alloc_stats_range_callback(ext2_filsys fs,
+       void (*func)(ext2_filsys fs, blk64_t blk,
+                                   blk_t num, int inuse),
+       void (**old)(ext2_filsys fs, blk64_t blk,
+                                   blk_t num, int inuse))
+{
+       if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
+               return;
+       if (old)
+               *old = fs->block_alloc_stats_range;
+
+       fs->block_alloc_stats_range = func;
 }

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 613f0d1..9655cd8 100644 (file)
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -279,6 +279,12 @@ struct struct_ext2_filsys {
 
        io_channel                      journal_io;
        char                            *journal_name;
+
+       /* New block range allocation hooks */
+       errcode_t (*new_range)(ext2_filsys fs, int flags, blk64_t goal,
+                              blk64_t len, blk64_t *pblk, blk64_t *plen);
+       void (*block_alloc_stats_range)(ext2_filsys fs, blk64_t blk, blk_t num,
+                                       int inuse);
 };
 
 #if EXT2_FLAT_INCLUDES
@@ -674,6 +680,16 @@ extern void ext2fs_set_alloc_block_callback(ext2_filsys fs,
                                                              blk64_t *ret));
 blk64_t ext2fs_find_inode_goal(ext2_filsys fs, ext2_ino_t ino,
                               struct ext2_inode *inode, blk64_t lblk);
+extern void ext2fs_set_new_range_callback(ext2_filsys fs,
+       errcode_t (*func)(ext2_filsys fs, int flags, blk64_t goal,
+                              blk64_t len, blk64_t *pblk, blk64_t *plen),
+       errcode_t (**old)(ext2_filsys fs, int flags, blk64_t goal,
+                              blk64_t len, blk64_t *pblk, blk64_t *plen));
+extern void ext2fs_set_block_alloc_stats_range_callback(ext2_filsys fs,
+       void (*func)(ext2_filsys fs, blk64_t blk,
+                                   blk_t num, int inuse),
+       void (**old)(ext2_filsys fs, blk64_t blk,
+                                   blk_t num, int inuse));
 #define EXT2_NEWRANGE_FIXED_GOAL       (0x1)
 #define EXT2_NEWRANGE_MIN_LENGTH       (0x2)
 #define EXT2_NEWRANGE_ALL_FLAGS                (0x3)